Applications of Microfabrication in Biosensor Technology

Biomedical engineering, Nanotechnology

Griffith, Alun wyn

University:University of Glasgow

关键词: Biomedical engineering, Nanotechnology;   

Others  :  http://theses.gla.ac.uk/74763/1/11007682.pdf

来源: University of Glasgow

【 摘 要 】

This thesis investigates the application of microfabrication techniques in biotechnology, embracing two major methodologies: biosensing and dielectrophoresis. In the first instance, the miniaturisation of biosensors for use in aqueous solutions was explored, focusing on the issues of insulator deposition and metal multilayer adhesion. Two different immobilisation strategies were used. The first involved the binding of the electroactive protein, cytochrome c, to a self-assembled monolayer in order to measure the cellular production of superoxide. The second was the entrapment of an enzyme, glucose oxidase (EC 1.1.3.4), within a polypyrrole film as the core of an amperometric sensor for glucose. In the latter case, a novel analytical technique was developed for characterising the sensor interface involving the use of XPS and FTIR. The technique was used to demonstrate the efficiency with the which enzyme could be bound within the film, and indicated a non-linear relationship between the concentration of entrapped enzyme and the its concentration in the polymerisation solution. To complement these studies, work in dielectrophoresis centred on methods for trapping and measuring single cell function within microfabricated electrode arrays. Although it was possible to hold a cell in close proximity to a biosensor array, difficulties concerning the sensitising of the electrochemical devices precluded measurements on single cells. However, by using a related technique it was possible, for the first time, to observe the dynamic activation of a single human neutrophil. The electrorotation technique was used to monitor changes in the physical character of the cell in order to identify the effects of chemotactic stimulation. Studies involving electrochemical and chemiluminescent measurements were performed to corroborate these findings.